Authorizing the use of a biometric card

ABSTRACT

Embodiments of the present invention provide a system and method for authorizing the use of a biometric transaction card. Specifically, embodiments of the present invention provide a biometric card having a biometric sensor to determine whether the biometric information (fingerprint) is from human skin. In a typical embodiment, the cardholder approaches a magnetic reader with the card. The user places his/her finger on the SpO 2  sensor of the card. The sensor estimates the SpO 2  level. Card authorization is based, in part, on the estimated SpO 2  level.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of commonly-owned and co-pendingapplication Ser. No. 13/853,349, filed Mar. 29, 2013. The earlier filedapplication is itself a continuation application of commonly-ownedapplication Ser. No. 13/114,121, filed on May 24, 2011 (now U.S. Pat.No. 8,408,471, issued Apr. 2, 2013).

FIELD OF THE INVENTION

In general, the present invention relates to biometric cards.Specifically, the present invention relates to a system and method forauthorizing the use of a biometric transaction card.

BACKGROUND OF THE INVENTION

As global fraud concerns relating to credit cards continue to grow, manycard issuers are attempting to come up with more secure credit cards fortheir cardholders. Existing methods for combating fraud still, at times,leave merchants and banks vulnerable. One attempt at producing a moresecure card is the biometric card. A biometric card is similar toexisting cards but will also contain information about the cardholder'sbody, such as a fingerprint. However, reports have surfaced that somefingerprint readers can be fooled using non-human contact, such as a gelmold.

SUMMARY OF THE INVENTION

In general, the embodiments of the present invention provide a systemand method for authorizing the use of a biometric transaction card.Specifically, embodiments of the present invention provide a biometriccard having a biometric sensor to determine whether the biometricinformation (fingerprint) is from human skin. In a typical embodiment,the cardholder approaches a magnetic reader with the card. The card ispowered up when the user attempts to use the card. The user placeshis/her finger on the SpO₂ sensor of the card. The sensor includes a redlaser, an infrared (IR) laser, and a photodetector. The red laser andphotodetector are turned on. Analog-to-digital conversion on thereflective light scattering received by the photodetector is performed.The red laser is turned off and the infrared (IR) laser is turned on.Analog-to-digital conversion on the reflective light scattering receivedby the photodetector is performed. The IR laser and the photodetectorare turned off. The SpO₂ level of the card user is estimated based onthe ratio of reflective scattering from the red and IR red lasers. Cardauthorization is based, in part, on the SpO₂ level.

The present invention relates to biometric transaction or authorizationcards including, but not limited to, credit cards, debit cards, giftcards, and identification cards. Any type of card within the scope ofthe present invention may be used.

A first aspect of the present invention provides a biometric card havinga biometric sensor used for authorizing the use of the card, comprising:a biometric fingerprint imager, comprising: a fingerprint sensorconfigured to sense a fingerprint of the card user; an authenticatorconfigured to authenticate the sensed fingerprint information; abiometric sensor, comprising: a red laser configured to emit a firstlaser light; an infrared (IR) laser configured to emit a second laserlight; at least one photodetector configured to generate a firstphotocurrent signal based on the reflective scattering of the firstlaser light and generate a second photocurrent signal based on thereflective scattering of the second laser light; an analog-to-digitalconverter configured to convert the first photocurrent signal to a firstwaveform and convert the second photocurrent signal to a secondwaveform; a processing component configured to estimate a SpO₂ levelbased on the ratio of the first and second waveforms; and an authorizingcomponent configured to authorize use of the card based on thefingerprint authentication and the SpO₂ level estimate.

A second aspect of the present invention provides a method for providinga biometric card having a biometric sensor used for authorizing the useof the card, comprising: providing a biometric fingerprint imager,comprising: a fingerprint sensor configured to sense a fingerprint ofthe card user; an authenticator configured to authenticate the sensedfingerprint information; providing a biometric sensor, comprising: a redlaser configured to emit a first laser light; an infrared (IR) laserconfigured to emit a second laser light; at least one photodetectorconfigured to generate a first photocurrent signal based on thereflective scattering of the first laser light and generate a secondphotocurrent signal based on the reflective scattering of the secondlaser light; an analog-to-digital converter configured to convert thefirst photocurrent signal to a first waveform and convert the secondphotocurrent signal to a second waveform; a processing componentconfigured to estimate a SpO₂ level based on the ratio of the first andsecond waveforms; and an authorizing component configured to authorizeuse of the card based on the fingerprint authentication and the SpO₂level estimate.

A third aspect of the present invention method for authorizing the useof a biometric card, comprising: sensing a fingerprint of the card user;authenticating the sensed fingerprint information; estimating the SpO2level of the card user; and authorizing the use of the card based on thefingerprint authentication and the SpO₂ level estimate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will be more readilyunderstood from the following detailed description of the variousaspects of the invention taken in conjunction with the accompanyingdrawings in which:

FIG. 1 depicts a biometric card according to an embodiment of thepresent invention.

FIG. 2A depicts the front of a biometric card having a multi-sidedsensor according to an embodiment of the present invention.

FIG. 2B depicts the back of a biometric card having a multi-sided sensoraccording to an embodiment of the present invention.

FIG. 3 depicts a biometric card having a transparent sensor according toan embodiment of the present invention.

FIGS. 4A, 4B, and 4C depict SpO₂ level detection according to anembodiment of the present invention.

FIG. 5 depicts a vertical-cavity surface-emitting laser according to anembodiment of the present invention.

FIGS. 6A and 6B depict a photodetector according to an embodiment of thepresent invention.

FIGS. 7A, 7B, and 7C depict laser and photodetector integrationaccording to an embodiment of the present invention.

FIG. 8 depicts an operation timing diagram according to an embodiment ofthe present invention.

FIG. 9 depicts a flow diagram according to an embodiment of the presentinvention.

The drawings are not necessarily to scale. The drawings are merelyschematic representations, not intended to portray specific parametersof the invention. The drawings are intended to depict only typicalembodiments of the invention, and therefore should not be considered aslimiting the scope of the invention. In the drawings, like numberingrepresents like elements.

DETAILED DESCRIPTION OF THE INVENTION

Illustrative embodiments will now be described more fully herein withreference to the accompanying drawings, in which exemplary embodimentsare shown. This disclosure may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these exemplary embodiments areprovided so that this disclosure will be thorough and complete and willfully convey the scope of this disclosure to those skilled in the art.In the description, details of well-known features and techniques may beomitted to avoid unnecessarily obscuring the presented embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of this disclosure.As used herein, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. Furthermore, the use of the terms “a”, “an”, etc., do notdenote a limitation of quantity, but rather denote the presence of atleast one of the referenced items. It will be further understood thatthe terms “comprises” and/or “comprising”, or rectify “includes” and/or“including”, when used in this specification, specify the presence ofstated features, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

The phrase “card technologies” encompasses any technology which can beplaced on a card. Typically, we think of a plastic bank card or creditcard, though there are many other materials and uses of cards. However,the card is usually for providing “access” to something, such as a bankaccount, credit card account, secure area, etc.

Most identity and transaction cards used today contain some basicdetails such as name, a photograph of the person's face and a referencenumber that allows the card to be matched against a central record heldby the card issuer. Other cards may also contain magnetic strips orbarcodes that can be used with other machines or to unlock doors so thatthe card acts like a key. A biometric identity card is similar toexisting cards but will also contain biometric information. Biometricinformation is information about a specific person's body, such as afingerprint.

The authenticity of the fingerprint needs to be checked to determinewhether the biometric information is coming from real human skin. SpO₂(arterial blood oxygen saturation level) is one of the important vitalsigns of a human. The normal SpO₂ level is more than 96%. A level under90% means that the person is in a fatal condition. SpO₂ is able to bemeasured easily by using a pulse oximetry method.

As indicated above, the embodiments of the present invention provide asystem and method for authorizing the use of a biometric transactioncard. Specifically, embodiments of the present invention provide abiometric card having a biometric sensor to determine whether thebiometric information (fingerprint) is from human skin. In a typicalembodiment, the cardholder approaches a magnetic reader with the card.The card is powered up when the user attempts to use the card. The userplaces his/her finger on the SpO₂ sensor of the card. The sensorincludes a red laser, an infrared (IR) laser, and a photodetector. Thered laser and photodetector are turned on. Analog-to-digital conversionon the reflective light scattering received by the photodetector isperformed. The red laser is turned off and the infrared (IR) laser isturned on. Analog-to-digital conversion on the reflective lightscattering received by the photodetector is performed. The IR laser andthe photodetector are turned off. The SpO₂ level of the card user isestimated based on the ratio of reflective scattering from the red andIR red lasers. Card authorization is based, in part, on the SpO₂ level.

Referring now to FIG. 1, a biometric card according to an embodiment ofthe present invention is depicted. Biometric card 100 includes biometricfingerprint imager 102, red laser 104, photodetector 106, and infrared(IR) laser 108. To authorize the use of a biometric transaction card,user biometric information is sampled with a separate fingerprintimager. A fingerprint sensor senses a fingerprint of the card user. Afingerprint authenticator authenticates the sensed fingerprintinformation. SpO₂ level is measured and used to determine the validityof the sampled biometric (fingerprint) information.

FIG. 2 depicts the front and back of a biometric card having amulti-sided sensor according to an embodiment of the present invention.The biometric card has a multi-sided sensor configuration. Card front200 includes front side 202 of sensor. Card back 210 includes back side212 of sensor.

FIG. 3 depicts a biometric card having a transparent sensor according toan embodiment of the present invention. Biometric card 300 includestransparent SpO₂ sensor placement. Sensor 302 contains only one set ofinfrared (IR) and red lasers. Sensor 302 contains, at most, twophotodectors. Separate front and back photodectors may be required.

FIG. 4 depicts SpO₂ level detection according to an embodiment of thepresent invention. Sensor 400 highlights red laser 402 activity.Transmission 404 shows the emission of light from red laser 402.Reflection 406 shows the reflective scattering of light from red laser402. Sensor 410 highlights infrared (IR) laser 412 activity.Transmission 414 shows the emission of light from IR laser 412.Reflection 416 shows the reflective scattering of light from IR laser412.

Hemoglobin is a protein in red blood cells that carries oxygen.Hemoglobin can be saturated with oxygen molecules (oxyhemoglobin), ordesaturated with oxygen molecules (deoxyhemoglobin). An infrared ray isabsorbed in deoxyhemoglobin and a red ray is absorbed in oxyhemoglobin.A pulse signal is obtained as the reflection of applied light to theskin. A red ray and infrared ray are used to obtain two kinds of pulses.SpO₂ is calculated using the amplitude of these two pulses. The SpO₂level is measured by placing the skin of a finger to the sensor.

Sensor 420 depicts full SpO₂ level detection using red laser 422, IRlaser 432, and photodetector 440. User finger 460 is placed on thesensor. Red laser 422 and IR laser 432 are alternatively turned on.Transmission 424 shows the emission of light from red laser 422.Transmission 434 shows the emission of light from IR laser 432.Reflection 450 shows the reflective scattering of light from red laser422 and IR laser 432.

To estimate the SpO₂ level of the card user, red laser 422 and infrared(IR) laser 432 alternatively emit light. Blood volume increases and thendecreases as the heart pumps blood through the user's finger. Bloodcells within the blood absorb and reflect varying amounts of the red andinfrared light depending the on the blood volume and how much oxygenbinds to the cells' hemoglobin. Photodetector 440 detects a portion ofthe reflective scattering of light and, in response, sends aphotocurrent to an analog-to-digital converter. The analog-to-digitalconverter digitizes the photocurrent to generate an optical waveform foreach wavelength. A processing component analyzes waveforms generated atboth red and infrared wavelengths, and uses ratio of the relativeabsorption to estimate the SpO₂ level of the card user.

FIG. 5 depicts a vertical-cavity surface-emitting laser according to anembodiment of the present invention. A vertical-cavity surface-emittinglaser is a type of semiconductor laser diode with laser beam emission502 perpendicular to the top surface. Laser 500 composition is made upof several layers in order to have the capacity to emit light. Laser 500is incased in metal 512. N-Substrate 510 is the underlying layer. Thelaser resonator consists of two distributed Bragg reflector (DBR)mirrors parallel to the wafer surface with an active region consistingof one or more quantum wells for the laser light generation in between.In this embodiment, P- and n-type Bragg reflectors (504 and 508,respectively) surround quantum well 506.

FIG. 6 depicts a photodetector according to an embodiment of the presentinvention. A photodetector is an optical detector that converts lightsignals to electrical signals, which can be amplified and processed.Semiconductor photodectors are the most commonly used detectors becausethey provide good performance and are small in size and cost. As shown,semiconductor 600 is made up of semiconductor region 602 and metal 604.The most common semiconductor photodetector is the PIN photodetector.PIN photodetector 610 has an intrinsic (very lightly doped)semiconductor region 614 sandwiched between a p-type region 612 and ann-type region 616.

FIG. 7 depicts laser and photodetector integration according to anembodiment of the present invention. Sensor 710 shows only film layer712. Sensor 720 further depicts red laser 722, photodetector 724, and IRlaser 726. Sensor 730 further depicts coating 732.

FIG. 8 depicts an operation timing diagram according to an embodiment ofthe present invention. The reflection of each laser emission must bemeasured. Red laser emission 802 is shown followed by IR laser emission804. Analog-to-digital conversion 806 converts each of the light signalsto a waveform. The ratio between red and IR reflections is used toestimate an SpO₂ reading.

FIG. 9 depicts a flow diagram according to an embodiment of the presentinvention. The card is powered up when the user is attempting to use thecard (step S1). The user places his/her finger on the SpO₂ sensor of thecard (step S2). The red laser and photodetector are turned on (step S3).Analog-to-digital conversion on the reflective light scattering receivedby the photodetector is performed (step S4). The red laser is turned offand the infrared (IR) laser is turned on (step S5). Analog-to-digitalconversion on the reflective light scattering received by thephotodetector (step S6) is performed. The IR laser and the photodetectorare turned off (step S7). The SpO₂ level of the card user is estimated(step S8). The estimated SpO₂ level is used as a factor in cardauthorization.

The foregoing description of various aspects of the invention has beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed and, obviously, many modifications and variations arepossible. Such modifications and variations that may be apparent to aperson skilled in the art are intended to be included within the scopeof the invention as defined by the accompanying claims.

What is claimed is:
 1. A method for authorizing the use of a biometriccard, comprising: powering up the card; sensing a fingerprint of thefinger; authenticating the sensed fingerprint information; sensing afinger on an SpO₂ sensor of the card; powering on a red laser and aphotodetector; performing analog-to-digital conversion on reflectivelight scattering from the red laser received by the photodetector;powering off the red laser; powering on an infrared (IR) laser of thecard; performing analog-to-digital conversion on reflective lightscattering from the IR laser received by the photodetector; powering offthe IR laser and the photodetector; estimating an SpO₂ level of thefinger; and authorizing the use of the card based on the fingerprintauthentication and the SpO₂ level estimate.
 2. The method of claim 1,wherein a sensor is used to estimate the SpO₂ level of the card user. 3.The method of claim 2, wherein the sensor includes the red laser, theinfrared (IR) laser, and the photodetector.
 4. The method of claim 3,wherein the red laser is a vertical-cavity surface-emitting laser. 5.The method of claim 3, wherein the infrared (IR) laser is avertical-cavity surface-emitting laser.
 6. The method of claim 2,wherein the sensor comprises a multi-sided configuration.
 7. The methodof claim 2, wherein the sensor comprises a transparent configuration. 8.The method of claim 3, wherein the red laser structure comprisesn-Substrate, n-type Bragg reflector, p-type Bragg reflector, and quantumwell layers.
 9. The method of claim 3, wherein the infrared (IR) laserstructure comprises n-Substrate, n-type Bragg reflector, p-type Braggreflector, and quantum well layers.
 10. The method of claim 3, whereinthe photodetector structure comprises an intrinsic semiconductor region,a p-type region, and an n-type region.
 11. The method of claim 1,wherein a fingerprint sensor senses the fingerprint of the card user,and an authenticator authenticates the sensed fingerprint information.12. The method of claim 1, further comprising: the photodetectorgenerating a first photocurrent signal based on the reflectivescattering of the red laser light; generating a second photocurrentsignal based on the reflective scattering of the IR laser light;converting, by an analog-to-digital converter, the first photocurrentsignal to a first waveform; converting, by the analog-to-digitalconverter, the second photocurrent signal to a second waveform; whereinthe SpO₂ level is estimated based on a ratio of the first and secondwaveforms.
 13. A method for authorizing the use of a biometric card,comprising: powering up the card; sensing a fingerprint of the finger;authenticating the sensed fingerprint information; sensing a finger onan SpO₂ sensor of the card; powering on a first laser and at least onephotodetector; performing analog-to-digital conversion on reflectivelight scattering from the first laser received by the at least onephotodetector; powering off the first laser; powering on a second laser;performing analog-to-digital conversion on reflective light scatteringfrom the IR laser received by the at least one photodetector; poweringoff the IR laser and the at least one photodetector; estimating an SpO₂level of the finger; and authorizing the use of the card based on thefingerprint authentication and the SpO₂ level estimate.
 14. The methodof claim 1, wherein a sensor is used to estimate the SpO₂ level of thecard user.
 15. The method of claim 14, wherein the sensor includes thefirst laser, the second laser, and the at least one photodetector, thefirst laser comprising a red laser, and the second laser comprising aninfrared (IR) laser.
 16. The method of claim 15, wherein the red laseris a vertical-cavity surface-emitting laser.
 17. The method of claim 15,wherein the infrared (IR) laser is a vertical-cavity surface-emittinglaser.
 18. The method of claim 14, wherein the sensor comprises amulti-sided configuration.
 19. The method of claim 14, wherein thesensor comprises a transparent configuration.
 20. The method of claim15, wherein the red laser structure comprises n-Substrate, n-type Braggreflector, p-type Bragg reflector, and quantum well layers; wherein theinfrared (IR) laser structure comprises n-Substrate, n-type Braggreflector, p-type Bragg reflector, and quantum well layers; and whereinthe at least one photodetector structure comprises an intrinsicsemiconductor region, a p-type region, and an n-type region.